Narcoleptic episodes in orexin-deficient mice are increased by both attractive and aversive odors

Orexin-deficient mice are an established animal model for narcolepsy. In human patients, narcoleptic events are mainly triggered by emotional events. However, the role of emotional stimuli in murine narcolepsy is not well understood. The present study investigated the effects of attractive and aversive odor stimuli, i.e., urine samples of coyote and female mice, on narcoleptic episodes (cataplexy, sleep attacks) in orexin-deficient mice. Here, we first demonstrate that exposure to both attractive and aversive odors significantly increase the number of narcoleptic episodes in orexin-deficient mice. This behavioral paradigm may be of high interest for studies focused on the question how emotions can trigger narcoleptic episodes.